Electronic tamper detection in a utility meter using magnetics

摘要

An arrangement for use in a utility meter includes a switch, a processing circuit, and a magnetic element. The switch is supported on a first meter structure. The switch has at least a first and second state. The switch is configured to transition from a first state to a second state responsive to a detected magnetic field of a first polarity, and to transition from a second state to a first state responsive to a detected magnetic field of a second polarity. The processing circuit is operably coupled to determine whether the switch is in the first state or the second state. The magnetic element is supported on a second meter structure configured to be physically connected to the first meter structure, the magnetic element positioned such that removal of the second meter structure from the first meter structure causes the magnetic element to expose the switch to a magnetic field of the first polarity.

主权项

1. An arrangement for use in a utility meter, comprising:
a bi-stable magnetic switch supported on a first meter structure, the bi-stable magnetic switch having at least a first and second state; a processing circuit operably coupled to determine whether the bi-stable magnetic switch is in the first state or the second state; a magnetic element supported on a second meter structure configured to be physically connected to the first meter structure, the magnetic element positioned such that removal of the second meter structure from the first meter structure causes the magnetic element to move toward and past the bi-stable magnetic switch; and wherein the magnetic element is positioned such that relative movement of the second meter structure with respect to the first meter structure associated with installation and removal of the second meter structure exposes the bi-stable magnetic switch exclusively to a magnetic field of a first polarity.